The very first scene, we see a Chevrolet Caprice taxi, which doesn't exist in 1973. Ralph's father is given a chance to help his son out one last time. Besides the thoughtful gifts he got for his family, he found out about the faulty trunk latch and the hospital visit and rescued the gifts from the trunk before anyone could steal them. He traveled back to before December 9th, re-wrapped and hid them in the basement where he knew his wife would find them, and rigged the fuse to fail at just the right time.
- This caused the timeline to break pretty badly as Christmas in 1973 was on a Tuesday, not Sunday.
- And gave Ralph an accidental look into the future of 1983, so his Imagine Spot about going to prison could have Sandy, Mark and Julie in period-accurate styles.
It seems rather coincidental that Ralph's car's trunk just happened to swing open while the family was getting Julie's eye injury taken care of. But remember—Frank had already gotten his family everything on their list before he passed away, and if the gifts hadn't been stolen, they would have been duplicates. So Frank, who was hanging around on our side to make sure his family could have a good Christmas without him, nudged the trunk open. Later, on Christmas Eve, he made sure the fuse blew so his wife would go down into the basement and find the gifts he'd already bought and wrapped. Having made sure his family was all right and enjoying Christmas, having seen his son succeed in his writing and step into his own shoes as patriarch, Frank Parker departs for the other side, satisfied.
It's also likely the elves here were also some of the kids who got pushed by them in the first film which explains why they're not as rude as in the first film as they don't want to give them the same experience.
